1. Field of the Invention
The present invention relates to an antistatic device of a display device, which has a high electrostatic discharge (ESD) speed and reduces consumption power, and to a method of manufacturing the same.
2. Discussion of the Related Art
With the advance of various portable electronic devices such as mobile communication terminals, smart phones, tablet computers, notebook computers, etc., the demand for flat panel display (FPD) devices applicable to the portable electronic devices is increasing.
Liquid crystal display (LCD) devices, plasma display panels (PDPs), field emission display (FED) devices, light emitting diode display devices, organic light emitting display devices, etc. have been developed as the FPD devices.
FIG. 1 is a diagram schematically illustrating a general LCD device, and FIG. 2 is a diagram illustrating an equivalent circuit of a related art antistatic device.
Referring to FIGS. 1 and 2, the LCD device includes a liquid crystal panel 10, in which a plurality of pixels are arranged in a matrix type to display an image, and a driving circuit unit (not shown) which supplies a signal and power for driving the liquid crystal panel 10.
In the LCD device, when static electricity is generated and input to a pixel, an image is not properly displayed, and a pixel and a line can be damaged. Therefore, an antistatic device 20 is parallelly connected to an input end of a data line DL and an input end of a gate line GL.
When static electricity is generated, the antistatic device 20 disperses the static electricity to protect the pixels in an active area. When high-voltage static electricity is generated, the antistatic device 20 first senses an electrostatic signal, and since an insulating layer of each of a plurality of internal thin film transistors (TFTs) is damaged, the antistatic device 20 protects the pixels which are formed in the active area.
The antistatic device 20 of the related art includes two switching TFTs 22 and 24 and one equalizer TFT 26.
The first switching TFT 22 and the second switching TFT 24 operate as a diode because a gate is diode-connected to a source, and prevent a current from flowing in both directions.
In the antistatic device 20 of the related art, the first switching TFT 22, the second switching TFT 24, and the equalizer TFT 26 are all formed of one kind of active layer.
When each of the first switching TFT 22, the second switching TFT 24, and the equalizer TFT 26 is an oxide semiconductor TFT, an operation speed based on an inflow of static electricity is high. On the other hand, in the oxide semiconductor TFT, a large amount of current is leaked, and for this reason, consumption power increases.
When each of the first switching TFT 22, the second switching TFT 24, and the equalizer TFT 26 is a amorphous silicon (a-Si) TFT, the amount of a leakage current is small. On the other hand, in the a-Si TFT, a response time based on an inflow of static electricity is slow, and for this reason, the static electricity is not quickly prevented.